Astrophotography

On Thursday 23 February we were treated to a twinkling talk on photographing the night sky by David Bishop from the Bradford Astronomical Society.

A whole new universe was opened up as he explained how to get images of distant objects - double stars, galaxies and nebulae many of which are not visible to the naked eye. Also 'nearby' objects like the moon, eclipses, transits of the sun and amazing alignments of planets were all shown.

And the equipment! Once you get used to the terminology it's not too bad. An 8" telescope has an 8" diameter objective lens, not an 8" focal length which explains the size of it; although that is reduced from enormous to just huge by Mr Newton's clever mirror design. So it will still go in the back garden on a tripod - but what a tripod! Mount it on a clever motorised computerised platform that compensates for the earth's rotation and you are off for your minutes-long exposures without star trails. After you have carefully aligned it, of course. The DSLR was the only familiar bit of kit, but you can graduate to specialist CCD cameras offering ISOs from 20,000 up to 100,000.

The results are amazing. Some created by stacking using multiple exposures corrected with multiple black exposures. Many of the images were taken in the centre of Shipley using a light pollution filter combined with physical screens to shield against individual street lights - astonishing!

Who knew there was a nebula the shape of North America? Or that a Coma Corrector is not a bit of medical kit. Or that Mr Charles Messier has catalogued everything up there.